This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. In this study, resequencing will be used to further characterize the MECP2 gene in individuals with the risk and protective haplotypes, searching for novel variants. These variants will then be assayed in an independent series of cases and controls. Additionally, chromatin immunoprecipitation will be used to determine the affects of these variants on DNA/protein complexes.